Calibration database.,

From: Flemming Videbaek (videbaek@sgs1.hirg.bnl.gov)
Date: Fri Nov 09 2001 - 09:59:07 EST

  • Next message: Stephen J. Sanders: "Re: Calibration database.,"

    Database problems
    
    As you may have seen Steve Sanders pointed to a problem with the calibration
    DB in so far data was not correctly transferred to his linux ppc.
    Christian and I have since looked at it further, and must admit that we made
    a mistake / design flaw back about 1.5 year ago.
    Unfortunately only now has it shown up.
    There seem to be several possibilities on how to proceed.
    
    a)       Ignore the problem i.e. DB access cannot be done to calibrations
    from linux ppc, solaris etc
    b)       Modification to code, that will disallow certain operation to be
    invalid on e.g.
    linux-ppc and solaris machines, but maintain access to db constants via the
    BrCalibration class only
    c)       Redesign the table Revision that hold the calibration data, as well
    as the internal
    storage. This implies the Cal DB has to be re-populated. It may be possible
    to do this
    by extracting the revisions, deleting and then re-creating, the easier would
    be to ask the limited cal done so far to be re-inserted e.g. DO thought it
    was ok for all the TO\F
    stuff.
    
    
     The solution a) is clear un-acceptable; though most work is done on the
    intel boxes, a
    not insignificant piece is done on platforms with opposite endian data
    storage.
    
     The solution b) does not really appeal to neither Christian nor me, and is
    therefore un-
    desirable.  The last solution is not convenient,. I have looked in detail at
    it and it is
    workable, even though it has some slight messy pieces (same information both
    in
    Parameter and Revision, which could lead to problems if people were to
    exploit low-
    level access). The last solution imposes some hard-ship on the ongoing
    analysis, but
    could probably be put in during a scheduled stopping and refilling of the
    DB.
    
     It is obvious something has to be done, and the sooner the better.
    
    In particular I will like comments back from people who have made actual
    valid
    calibrations (don't count pedestals- too easy) for tof, cherenkovs, tiles,
    si . I/we will be
    happy to provide you copies of the tougths made so far.
    
     Flemming
    
    
    ------------------------------------------------------
    Flemming Videbaek
    Physics Department
    Brookhaven National Laboratory
    
    tlf: 631-344-4106
    fax 631-344-1334
    e-mail: videbaek@bnl.gov
    



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